This invention relates in general to high frequency devices and in particular to a new and useful millimeter-wave circulator.
Millimeter wave circulators are usually designed as Y circulators and employed as nonreciprocal junctions, for example for decoupling transmitters from receivers, or a synchronizing millimeter wave source from a power amplifier.
The bandwidths of such circulators are typically about from 1 to 2%. Because of these bandwidths and since the resonant frequency of ferrite resonators primarily depends on the geometrical dimensions thereof, high requirements are to be imposed on the mechanical tolerances in the ferrite manufacture and mounting, if, for example, a minimum isolation is to be maintained at a given operating frequency. To enlarge the bandwidth, it is known to reduce the Q factor of the circulator arrangement which, however, always involves undesirably increased transmission losses.